Digital certificate adopts public key cryptosystem, that is, a pair of matching keys are used for encryption and decryption. Every user has a private key that only he has, and uses it to decrypt and sign; At the same time, it has a public key, which can be publicly used for encryption and signature verification. When sending confidential documents, the sender uses the receiver's public key to encrypt data, and the receiver uses its own private key to decrypt data. In this way, information can reach its destination safely and correctly. Even if it is intercepted by a third party, it cannot be decrypted because there is no corresponding private key. The encryption process is guaranteed to be irreversible by digital means, that is, only the private key can be used for decryption. RSA is commonly used in public key cryptosystems.

Users can also use their own private key to process information, because the key is only owned by themselves, resulting in files that others cannot generate, thus forming a digital signature. Using digital signature, you can confirm the following two points:

(1) The guarantee information is sent by the signer himself, and the signer cannot or cannot deny it;

(2) Ensure that the information has not been modified from publication to receipt, and the published document is authentic.

The role of digital certificate

Digital certificates can be used for sending secure e-mails, accessing secure websites, online securities, online bidding and purchasing, online contract signing, online office work, online payment, online taxation and other online secure electronic transaction processing and activities. The format of digital certificate generally adopts X.509 international standard.

Second, the function of digital certificate

Information secrecy

Business information in the transaction needs to be kept confidential. If you know the account number and user name of the credit card, you may be stolen. If the information of ordering and payment is known by competitors, you may lose business opportunities. The digital security certificate issued by CA Center ensures the confidentiality of information in e-commerce information dissemination.

Identity certainty

The two sides of online transactions are probably strangers, thousands of miles apart. To make the transaction successful, we must first be able to confirm the identity of the other party and consider the merchant.

The customer can't be a liar, and the customer will worry that the online shop is not a dirty shop playing tricks. Therefore, it is the premise of the transaction to confirm the identity of the other party conveniently and reliably. For banks, credit card companies and sales stores that provide services to customers or users, in order to carry out service activities safely, confidentially and reliably, identity authentication must be carried out. The electronic signature issued by CA center can ensure the identities of both parties in online transactions, and banks and credit card companies can confirm their identities through CA authentication and conduct online business with confidence.

undeniable

Due to the ever-changing business conditions, once the transaction is reached, it cannot be denied. Otherwise, it will inevitably harm the interests of one party. For example, ordering gold,

When placing an order, the price of gold was low, but after receiving the order, the price of gold rose. If the acquirer can deny the actual time of receiving the order, or even the fact of receiving the order, then the orderer will suffer losses. Therefore, the digital security certificate issued by CA Center ensures the non-repudiation of all links in the communication process of electronic transactions, so that the interests of both parties are not harmed.

Not to be tampered with.

Transaction documents cannot be modified, such as ordering gold mentioned in the above example. After receiving the order, the supplier found that the price of gold rose sharply. If the contents of the document can be changed and the order number is changed from 1 ton to 1 gram, it will benefit greatly and the ordering unit may suffer losses.

Therefore, the digital security certificate issued by CA center also ensures that the electronic transaction documents cannot be modified to ensure the seriousness and fairness of the transaction.